Electric circuit breaker



0. MAYR Inventor: Otto Qg'r X 6. J

is Attovneg.

April 27, 1937.

ELECTRIC CIRCUIT BREAKER Filed June 16,

. a T a Patented Apr. 27, 1937 PATENT OFFICE ELECTRIC CIRCUIT BREAKER Y Otto Mayr, Berlin-Karlshorst, Germany, assignor to General Electric Company, a corporation of New' York Application June 16,

1936, Serial No. 85,568 I In Germany July 15, 1935 5 Claims.

My invention relates to electric circuit breakers, more particularly to the contact structure thereof, and has for its principal object the provision of an'improved circuit breaker of the type wherein 5 the contacts engage in plug and socket relation.

In circuit breakers of the aforesaid type, the socket or fixed contact is generally formed of segments circumferentially located about the movable rod contact and biased into engagement therewith by springs, either individually, or as a group by a surrounding garter-type spring. In these arrangements the electrical connections and the mechanical mountings between the segments' and the corresponding breaker terminals may be complicated and expensive, both in construction and maintenance.

In accordance'with my invention, these disadvantages are overcome by providing resilient positioning means for each pair of a plurality of segments forming a ring shaped contact, said means positioning said segments with respect to and biasing them into contact engagement with both the coacting. movable rod contact and the stationary conducting structure associated with the corresponding breaker terminal.

My invention will be more fully set forth in the following description referring to the accompany- """ing' drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

Referring to the drawing, Fig. l is an elevational view, partly in section, of a circuit-breaker oi the gas-blast type embodying the present invention; Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1; Fig. 3 is aview similar to Fig. 2 illustrating a modified form or the contact struc ture, and Fig. 4 is another similar view'showing a more simplified form.

In Fig. 1 there is shown, by way of example, a circuit breaker of the gas-blast type comprising a cylindrical insulating casing l in which are mounted the relatively fixed contact structure 2 and the movable contact structure 3, comprising in the present instance a rod contact. The breaker is shown in the open circuit position, and in the closed circuit position the rod 3 is elevated by suitable operating means (not shown) so as to engage the fixed contact structure 2.

The fixed contactstructure 2, referring also to I Fig. 2, comprises a plurality of pairs of coacting segments 4 adapted to surround and engage the rod contact 3 in the closed circuit position. Each pair of segments 4 is interconnected by resilient supporting and positioning means comprising a through-bolt 5 and a pair of springs 6. For convenience in assembly and maintenance, the heads of the through-bolts 5 are elongated, as contrasted with the conventional circular shape, and coact with cup-shaped members I which provide seats for the springs 6 bearing against the segments 4. The cup members I are provided with elongated slots corresponding to the size of the bolt heads so that during assembly the bolt heads are merely inserted through the slots and turned 90 degrees, thereby holding the springs in compressed position with respect to the through bolt and segments 4.

In addition to maintaining the segments in contact engagement with the rod 3, the springs 6 also bias the lateral clamp-shaped extensions 4' of the segments into contact engagement with a conducting contact carrier or support 8. The support 8 in the present instance comprises a loopshape rod structure, the lower free arms of which are engaged by the segments 4 and the upper part suitably connected to the breaker terminal stud 9.

From the foregoing, it will be clear that the electrical connection between the breaker terminal 9 and the segments 4 constituting the main fixed contact structure is considerably simplified in that a number of bolted and flexible connections, previously used, are avoided. Furthermore, segments 4 which {necessarily have a limited amount of movement because of occasional contact misalinement are not only in good electrical engagement with the support 8 but also are mechanically clamped thereto by the radially disposed extensions 4' for holding the segments in proper position.

The electrical connection between the other terminal and the rod contact 3 may be made in a similar manner. Here the contact segments 4 are in sliding engagement at all times with the rod. 3 and are electrically and mechanically connected to the loop-shaped conducting support 8 in the manner above described. The support 8, which is fixed as in the previous instance, is connected to the other breaker terminal I 0 by means of a braided conductor II which is connected to a conducting end cap l2 forming part 7 of the terminal structure. The rod 3 is guided through the lower end of the support 8 at 8' and the cap l2 for vertical reciprocal movement.

The gas blast feature of the breaker, which is shown merely by way of example, comprises a pipe [3 communicating with a suitable source of fluid pressure (not shown) leading into the lower end of the casing I through the cap I 2. The fixed contact structure 2 is preferably mounted in a suitable baiile structure ll iorming with the segments [a nozzle-shaped passage I! through which gas may exhaust from the lower part of the casing to the upper part beyond the batlle. Circuit interruption is efiected by lowering the rod 3 to the open position coincident with the admission of high pressure gas through the pipe I. The arc between the contacts I and I is interrupted by the gas blast through the passage i5.

A muiller device is provided at the upper part oi the casing 1 beyond the exhaust from the passage ll comprising a pair of spaced perforated plates It forming a space containing a plurality of small rings II. The muiliing device is positioned above the contact carrier I on the terminal stud 8. A cup-shaped gas deflecting member I! is likewise secured to the stud I above the muifler and is positioned by a stud bushing ll between the lower side thereof and the carrier 8, anda nut 2| threaded on the bolt I. With this arrangement, the high velocity gas exhaust from the e II on circuit.interruption is silenced to a great extent by the muiliing device at lt-l'l, the exhaustgases finally issuing from the topo! the casing l around the outer periphery thereof.

The assembly 0! the above described structure withinthecasing I maybeaccomplishedinany suitable manner. I have shown the fixed and movable contact structures secured within the insulating casing to a pairof metal sleeves 2| and 22, respectively, at the upper and lower ends of the casing I. The bafile structure I andthe muiliing device are suitably secured to the inner wall of the sleeve II, as indicated, are the contact retaining spider II and the contact carrier supporting strut 24 to the lower sleeve 22.

Where a contact structure of higher current carryin capacity is required, the arrangement shownbyFig. Bmaybeusedwherein iourpairs of contact segments are circumierentially disposed about the rod contact 3. In this arrangement, as in the previous case; each pair 0! contact segments is provided with resilient positioning means comprising a through-bolt and biasing springs I and 0, respectively, and is resiliently clamped to a depending member of the contact carrier I. There is in this case four such members dependingtromtheterminalstudlandspacediio degrees apart.

Fig. 4 illustrates a simplified i'orm of contact structure wherein a single pair of contact segments 4 makes contact between the movable rod 3 and the stationary contact support I, the biasing and supporting means for the segments being the same as above described.

It should be understood that my invention is 7 not limited to specific details of construction and arrangement thereof herein illustrated, and that chames and modifications may occur to one skilled in the art without departing irom the spirit of my invention.

whatlclaimasnewanddesiretosecm'eby Letters Patent 0! the United States. is:-

1. An electric circuit breaker comprising coacting fixed contact structure and a movable rod contact, said fixed contact structure including a. terminal, a plurality of conducting members connected to and extending from said terminal, a pair or contact segments ior enga in each 'conducting member so as to clamp said member, said pairs of segments surrounding the movable rod contact in the closed circuit position, and resilient positioning means ior each pair of said able rod contact arrangedto be in slidingcontact engagement therewith. said fixed contact structure including a plurality of pairs of contact segments arranged circumierentially about said rod contact, said segments having extensions radially disposed with respect to said rod contact, conducting means engaged in clamping relation by the extensions of each pair of segments, and resilient positioning means for biasing each pair of segments into contact engagement with said rod contact and conducting means respectively.

3. An electric circuit breaker comprising coacting fixed contact structure and a movable rod contact, said fixed structure including a terminal member, a loop-shaped contact carrier connected to said terminal member, a pair oi contact segments engaging in clamping relation each arm or said loop-shaped members, said contact segments arranged circumi'erentialLv about said rod contact in closed circuit position and adapted to be in relative sliding engagement therewith, and resilient means for biasing each pair of contact segments into contact engagement with said rod and into clamping engagement with said contact carrier arm.

4. .An electric circuit breaker comprising a fixed contact structure and a coacting movable rod contact, said fixed contact structure including a terminal, conducting means connected to said terminal, a plurality of contact segments arranged circumierentially about said movable rod contact in the closed circuit position, each pair of said contact segments provided with means for conducting means electrically connected to said terminal, and a plurality of pairs of contact'seg- I ments resiliently biased and similarly arranged to engage both said rod contact and conducting means respectively, said last-named segments being in sliding contact engagement with said rod in both the open and closed circuit positions at said circuit breaker. v

5. An electric circuit breaker or the gas-blast type comprising a casing, relatively movable contacts co -acting within said casing and means for admitting gas under pressure to one end of said casing for exhausting at the other end 0! said casing, said fixed contact structure including a bailie disposed transversely oi said casing provided with a central passage, a plurality of contact segments disposedcircumierentially about and extending radially with respect to said passage so as to form with said passage a nosxle-like exhaust opening through said bailie,a terminal disposed at the exhaust end of said casing. a contact carrier connected to said terminal and extending to said baflie, and resilient positioning means for biasing each pair of segments into contact engagement with said movable rod contact in the closed circuit position and into clamping engagement with said conducting means.

O'I'IO MAYR. 

